1. Field of the Invention
This invention relates to a powder transport device for use in an image forming devices, such as a copier, a facsimile or a printer. More specifically, this invention relates to a powder transport device including a mass powder storing part, and to an image forming system including the powder transport device.
2. Description of the Related Art
Conventionally, supply of toner to an image forming device is performed using a toner container which has a 0.5-2 liter capacity. This is because exchange of toner container is performed by the user and the use of the toner container having such capacity is considered suitable in the light of operability of the user.
However, if the toner container having such capacity is used, there is a problem that exchange of toner container must be performed frequently by a certain user, such as a print service company, who consumes a lot of toner.
Therefore, it is desired to reduce the frequency of exchange of toner container. To obviate the problem, Japanese Patent No. 3534159 discloses a toner device which is adapted for accommodating two or more toner containers. With this toner device, the period of consumption of all the toner containers can be prolonged. The empty-state toner containers can be exchanged even during image formation of the image forming device, and it is possible prevent operation of the image forming device from being stopped unnecessarily. However, if the capacity of each toner container in this toner device is the same, the frequency of exchange remains unchanged. Reducing the frequency of exchange of the toner containers is difficult for this toner device.
Moreover, the toner container disclosed in Japanese Laid-Open Patent Application No. 2005-024622 has a large capacity, and it is possible to reduce the exchange frequency of the toner container because of the large-capacity container. However, since toner is discharged from the lower part of this toner container and supplied to a toner receiving device, if separation or breakage of the toner piping occurs, much of the stored toner may be scattered.
Moreover, it is desired to increase the amount of storage of a mass toner storing container for heavy-consumption users to an amount larger than that of a conventional toner storing container. The increased amount of the storage mass toner storing container is, for example, in a range of 5-100 liters in capacity. However, toppling of the mass toner storing container may take place during conveyance or storage, earthquake, etc.
Furthermore, if an inexperienced worker mistakes connecting operation of the mass toner storing container at the time of exchange work, it is likely that the amount of scattering of the stored toner increases, the joint portion of the container is damaged.